Despite having privileged access as the head of the US Department of Justice, hand-picked by Trump, Sessions said he knows about as much about Russian hacking as the average American.

The Senate Intelligence Committee hearing is the latest step in multiple ongoing investigations into Russian meddling in last year's USA presidential election and Trump's firing of another FBI chief, James Comey, who was heading the investigation into Russian meddling when Trump dismissed him a month ago.

Such a move would be complicated and potentially politically explosive.

Sessions recused himself from the Russian Federation probe after his two meetings with the ambassador were revealed - though he was involved in former FBI Director James Comey's firing, which President Trump admitted was all about Russian Federation.

Trump apparently felt Session's recusal was unnecessary and only served to bring more negative attention to his administration in relation to the Russian Federation probe.

Harris was silenced last week during former Federal Bureau of Investigation director James Comey's testimony because she would not allow him to properly answer questions either.

Democratic Sen. Ron Wyden of OR aggressively asked Sessions about suggestions arising from Comey's testimony last week that there was something "problematic" about his recusal.

Addressing allegations that he had unreported meetings with Russian officials while he advised the Trump campaign, Sessions said he had already acknowledged two meetings a year ago with Ambassador Sergey Kislyak.

But the revelations forced Sessions to recuse himself from the Russian Federation investigation in March, and it is now being handled by a special counsel.

Also, the two were together on issues like immigration and trade when, at the time, Sessions was often a voice in the wilderness among other Senate Republicans.

The attorney general testified on Capitol Hill on Tuesday as the FBI investigation into Russia's influence on the presidential election continues.

According to sources, Comey said he met with Kislyak a third time.

It comes as political intrigue pulses through the U.S. capital following explosive testimony by Comey before the same panel last week, and as Trump has expressed frustrations with Sessions, one of his earliest high-profile campaign backers. Comey testified that in the privacy of the Oval Office, the President asked him to let the investigation into former national security adviser Michael Flynn drop.

Sessions told Trump he was "honored" to be able to serve him.

He may also face questions about comments by Trump confidant Chris Ruddy, chief executive of Newsmax, who suggested Monday that the president was considering firing Mueller, the special counsel appointed by the Justice Department to lead the FBI's Russian Federation probe. He does not acknowledge the unanimous conclusions of the US intelligence community that Russian Federation massively intervened in our election. The White House has denied any collusion with Moscow.

Instead he maintained that he was "not stonewalling", but "following the historic policies of the Department of Justice". But, because Sessions has recused himself, the question could easily fall to Rosenstein.

Rosenstein said that if he fired Mueller, he would be required to explain it in writing. He added: "the false attacks, the innuendo, and the leaks, you can be sure, will not intimidate me".

Rosenstein said that if the president ordered him to fire the special counsel handling the Russian Federation investigation, he would only comply if the request was "lawful and appropriate". "I was honestly concerned that he might lie about the nature of our meeting, and so I thought it really important to document", the ex-FBI director testified. She asked whether he has seen "any evidence of good cause" to fire Mueller. "I appointed him. I stand by that decision". "I will defend the integrity of that investigation".

Newt Gingrich, a former Republican House of Representatives Speaker and Trump ally who initially praised the choice of Mueller, complained this week that Mueller had hired too many Democrats.

From left, Attorney General Jeff Sessions and Labor Secretary Alexander Acosta, listen as Vice President Mike Pence, right, speaks during a Cabinet meeting with President Donald Trump, Monday, June 12, 2017, in the Cabinet Ro.